Network Load Balancing at its best for SharePoint 2010

Configuring NLB for SharePoint 2010 

The concept behind Network Load Balancing is pretty simple: Each server in a Load Balancing Cluster is configured with a 'virtual' IP address. This IP address is configured on all the servers that are participating in the load balancing 'cluster' (a loose term that's unrelated to the Microsoft Cluster Service). Whenever a request is made on this virtual IP a network driver on each of these machines intercepts the request for the IP address and re-routes the request to one of the machines in the Load Balancing Cluster based on rules that you can configure for each of the servers in the cluster. Microsoft this process Network Load Balancing (NLB). Figure 1 shows how the process works graphically.

A network load balancing cluster routes requests to a single virtual IP to available servers in the load balancing cluster. Note that each machine is self-sufficient and runs independent of the others duplicating all of the resources on each server. The database sits on a separate box(es) accessible by all servers.

actually no need to configure a heart-beat adapter address for NLB. Single adapter is enough with an IP address on each server which can be part of your server LAN address. Importantly make sure that if your network switch is multicast enabled then the NLB Cluster mode needs to be in multicast mode or else the communication will be interrupted. If multicast is not enabled on switch, opt for unicast cluster mode in NLB.

out of umpteen blogs I referred, let me share few of the helpful blogs which I felt had acted upon and suited our infrastructure without much hassles.. 

reference 1

video ref 2
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- make sure you configure port rules on NLB for better performance.

- configure perfmon to verify the load on each cluster web front end servers.

Best Practice: SharePoint 2010
Three-Tier-SharePoint-2010-Architecture